Weight indicator



Oct. 20,

F. L. SCOTT WEIGHT INDICATOR Filed July 5. 1921 E L. Scott INVENTOR HIS ATTORNEY.

Patented Oct. 20, 1925. I

UNITED STATES PATENT @OFFICE.

FLOYD L. SCOTT, OF HOUSTON, TEXAS, ASSIGNOR T0 HUGHES TOOL COMPANY, OF HOUSTON, TEXAS.

WEIGHT INDICATOR.

Application filed July 5, 1921.

To all whom it may concern:

Be it known that I, FLOYD L. Soon, a citizen of the United States, residing at Houston, Harris County, Texas, have invented a certainnew and useful Improvement in \Veight Indicators, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in weight indicators and is designed for particular application to derricks used in oil well drilling.

To obtain the best results in well drilling for oil, gas, sulphur and the like it is important that the driller have some way of determining, with a close degree of accuracy, the amount of load resting upon the drill or sustained by the cable.

The ob'ect of my invention is to provide a device or indicating the load, which may be easily and quickly attached to a-derrick 'upon which the weight carrying cable is supported.

Another object is to so apply such an indicator that it will not interfere with the handling of the line but may be secured in the derrick alone.

Referring to the drawing herein: In Fig. 1 I have shown my invention as applied to a well derrick such as is in ordinary use in oil fields, certain parts of the derrick and drilling apparatus being broken away, and others shown diagrammatically. Fig. 2 is a broken view, illustrating another embodiment thereof.

The derrick 1 is of the usual frame construction. The derrick platform is supported on side sills 2 and 3. The upper end of the derrick supports a crown block 4, having a plurality of sheaves or pulleys 5 thereon. A hoisting drum 6 near the'platform of th derrick serves to reel up the cable 7. This cable passes up over one of the sheaves of the crown block 4 and down around one i of the sheaves of the travelling block 8 and back over another sheave of the crown block. This operation is repeated and the line is thus threaded back and forth from crown block to travelling block a number of times, the forward end being finally extended downward and tied at 9 to the upper bail of the travelling block.

To the lower end of the travelling block is Serial No. 482,311.

secured the swivel 10, supporting the rotary drill stem 11, which is adapted to be operated by a rotary shown diagrammatically at 12. This construction is the usual and common type of rig employed in oil field operations.

In using my invention in relation to an equipment such as has been described, 1 contemplate securing a pulley 13 at the upper end of the derrick. A cable 14 may then be secured at 21 to one of the sills of the derrick. The forward end of this cable is passed around the pulley 13 and drawn down tightly and secured at its opposite end to an indicator.

Any usual type of spring weight indicating device may be employed. I have shown a hand- 15 pivoted at 1 6" to a support 17. The forward end of this hand is positioned to move along a dial 18 graduated to show weight in pounds. The opposite end of the hand 15 is extended rearwardly and has connection at 19 with a dash-pot 20 tosteady the movements of the hand.

The cable is attached to the hand 15 through a spiral spring 21 secured at 22 adjacent the pivot 16 and between the same and the dash-pot. A second spring 23 is socured in the opening 22 and extended downwardly for attachment to some fixed support such as the sill 2.

The operation of my invention depends upon the resiliency of the derrick in combination with the apparatus described. \Vhen a heavy load is sustained by the cable upon the crown block of the derrick. the said der rick is compressed slightly in a longitudinal direction. \Vhen the weight is released, the derrick will spring upwardly to its original position. It has been found that the derrick framework makes a sort of spring the compression or expansion of which by the load may be measured with a fair degree of accuracy. As the cable 14 is capable of adjustment. it may be drawn tautso that the hand 15 will indicate the zero point on the dial when no load is sustained. The dial may be so graduated that variations in the weight will be indicated in an obvious manner. The springs 21 and 23 assist in somewhat. diminishing the force of the shock of ing of the drill stem in rapid rotation on hard rock. The amount of load on the cable can thus be readily calculated; On the other hand, by watching the dial the load released from the cable-and allowed to rest on the bit at the bottom can be easil seen.

This conception of using t e frame of a.

derrick as a. part of a Weight indicating combination may be carried out in other ways than the one just described as will be obvious. In Fig. 2 I have shown another embodiment of this idea. In this form of my invention I contemplate transmitting the contraction or expansion of the derrick frame under ,the load to. the indicator through a rigid rod or pipe 25 secured at 26 to the crown block support. It is slidably supported in guides 27 on the derrick frame and the lower end is preferably received in a sleeve 28 in whichit may be adjustably secured by means. of a hand screw 29.. The lower end of the sleeve. 28 furnishes a chamher to house a spiral spring 30. This spring beam at the upper and upon a shoulder 31 within the sleeve and 'atits lower end against a plunger on the upper end of a rack 32 said rack being supported at its lower end upon a spiralspring operate an in icator hand on a dial 34 by some means such as a small pinion on the pivot pin'of the hand. The exact construction of the indicating device is not in itself an important part of this invention, the idea being to usesome ty of indicator and to operate it by means 0 a connection with the derrick, whereby the frame of the derrick becomes the main spring, the compression or expansion of which actuates 'the'indicator.

The advantage ofthis type of indicator is that it can be quickly installed on any derrick without in any way interferingwith the cable or the drilhn apparatus. The indicator will be conveniently at hand where the the formation being.

driller can read it and ascertain when. the proper load is resting on the bit, and when any variations occur in the load dueito accident or through chan i1 ig the character of Having thus described my invention, the objects and! advan s Wlll be apparent without further description. I

.What' Iclaim as new and desire to V by Letters Patent is:

1. A weight indicator for well drilling,

comprising a derrick, a derrick platform, a dial, anindicating hand ivoted tomove relative to said dial, a cab e secured at one end to said derrick platform, the'other endbeing passed over a ulley at the upper end of the derrick and rought down andattached resiliently to said-hand adjacent 'its pivotal'point, and means to steady the action of said and. 7

2. In a weightindicator for well drilling, a derrick, a load operating means thereon, a support, anindicatin'ghand pivoted to said 33; The rack isadapted to' 3. In a device of the character described, a

well derrick, a platform at the lower end thereof, a pulle at the upper end, a weight indicat'or,'a cable platform, the other end being passed around said pulley and brought down and attached to said weight indicator and load supporting means on said derrick.

4. In a device ofthe character described, the combination of a well derrick for handling loads, with a load indicating device, comprisin a support, an indicating hand pivoted t ereto, a graduated dial at one end of said hand, a cable secured toward the other end of said hand and having engagement with the upper end of said derrick and resilient means to hold said hand normally at zero point on said dial and to govern the movement of said hand when the tension on secured at one end to said the said cable is varied by the load suspended.

5. In a device of the character described, a well derrick, load su porting'means thereon, a support, a loa -1ndicat1ng device on said support, comprisin a graduated dial 1 6. A weight indicating combination for well drilling means, comprisin a derrick, a derrick platform, and a loa supporting meanssecured to the upper end of said derrick, a weight indicator positioned adjacent the lower end of said derrick, and including a dial, an indicatinghand pivoted to move relative to said dial, and means separate from the derrick and connecting the upper end *thereof with said indicating hand, whereby the variations in compression of the derrick, due to the load thereon, will result in the movement of said indicatin hand. .7. In a device of the character 5 end thereof, a'wei ndicating device attached to the derric adjacent the lower end' thereof, a-load sup orting means secured. to

the upper end of t e derrick, and separate escribed, a well derrick havingia platform at the lower iao means connectin the up r endof the derrick with the in icating evice, whereby the variations in compression of the derrick due to the load thereon will result in the actuation of the indicating means.

In testimony whereof, I hereunto aflix my signature this the 28th day of June, A. D.

FLOYD L. SCOTT. 

